A one-way dry filter is installed in a refrigerating pipeline flowing in one way and is usually installed between a condenser and an expansion valve. It can effectively prevent from gathering pollutants in a flowing direction, and can absorb moisture in a refrigerant. By means of combined design of drying and filtration inside the one-way dry filter, filtered and soluble substances can be effectively prevented from entering key components of a refrigerating system, so as to ensure that the system runs under an optimal state.
The structure of the one-way dry filter in the prior art is as shown in FIG. 1 and FIG. 2. The one-way dry filter comprises a barrel 1′, a first end cover 2′ and a second end cover 3′ provided at two ends of the barrel 1′, and a filter layer 4′ and a dry layer provided in the barrel 1′ in sequence, wherein the dry layer comprises a first filter plate 5′ and a second filter plate 6′, a dry chamber is formed between the first filter plate 5′ and the second filter plate 6′, and a molecular sieve is provided in the dry chamber. The one-way dry filter in the related art has the following problems.
Because an outlet of the one-way dry filter is provided in the middle of a cross section of the barrel and the second filter plate 6′ abuts against the second end cover 3, an area in the barrel along a central line thereof forms a low-pressure area when the refrigerant flows through the one-way dry filter. In the presence of the low-pressure area, the refrigerant will flow to a central part of the second filter plate 6′ (as shown in an arrow direction in FIG. 1) under the action of pressure regardless of a flowing direction of the refrigerant out of the first filter plate 5′. The flowing direction of the refrigerant enables filtered impurities to be accumulated in the middle of the first filter plate 5′, and enables the resistance of the refrigerant to ascend linearly. Even if the middle resistance of the first filter plate 5′ is over-large, the refrigerant flows to an inner wall of the barrel 1′, but the refrigerant will be urged to flow to the middle of the first filter plate 5′ under the influence of the pressure difference. In conclusion, the utilization rate of the first filter plate 5′ of the one-way dry filter in the related art is low, and meanwhile, the pressure is increased due to accumulation of the filtered impurities in the middle of the first filter plate 5′, thereby affecting the service life of a product.